This invention relates generally to apparatus and methods for testing cooling systems, and particularly engine cooling systems.
Cooling systems must be checked from time to time for leaks and proper functioning. Conventional testing equipment typically falls into two categories, namely, pressure kits and vacuum kits. Pressure kits are used to pressurize a cooling system to some pressure greater than atmospheric pressure (e.g., 15 psig), following which the pressure is monitored to see if it drops, indicating a leak of fluid (liquid or air). Leaks are generally easy to locate using this type of kit, but refilling the system with liquid after it has been repaired may cause air bubbles. Vacuum kits are used to de-pressurize a cooling system (i.e., reduce system pressure to below ambient pressure, or vacuum), following which the pressure is monitored to see if it increases, indicating a leak of fluid (liquid or air). Leaks are harder to find using this method, but refilling after repair is much easier, since the vacuum can be used to refill the system without introducing air bubbles. Depending on the situation, it is sometimes more desirable to use the pressure method and sometimes more desirable to use the vacuum method.
There is a need, therefore, for a pressure testing system which can be used in either a positive pressure mode or a negative pressure (vacuum) mode, as the situation requires.